The present invention generally relates to wireless area network technology, and more particularly relates to a wireless metropolitan area network (WMAN).
Computer technology is evolving. One aspect of this evolution is a move from stationary to portable computing devices, and in certain instances, moving to mobile computing devices. To facilitate portable and mobile computing, the computer industry is moving toward wireless communication. Technological efforts along these lines include cellular and wireless local area network (LAN) architectures.
In a cellular LAN architecture, a significant amount of infrastructure is needed. Using code division multiple access (CDMA), cellular systems are conventionally deployed with a single carrier signal in core population centers. However, to support an increase in demand for communication, a second carrier signal is being added to such CDMA cellular systems in major markets. Unfortunately, high-speed data applications consume a significant portion of bandwidth. Where voice and data communication share bandwidth, data communication is conventionally preempted by voice communication to avoid revenue loss. Accordingly, a new and extensive infrastructure addition is being evaluated to support this increase in demand for wireless data communication, especially with respect to mobile computing. Exacerbating this demand for bandwidth is a limitation of CDMA, which is bandwidth limited for vehicular mobility on the order of about 76.8 kilobits per second (Kbps) for second generation CDMA and 384 Kbps for third generation CDMA. By vehicular mobility, it is meant speeds in excess of 5 kilometers per hour. For non-mobile applications, third generation CDMA will support 2 megabits per second (Mbps).
Examples of wireless network architectures are xe2x80x9cRicochetxe2x80x9d and xe2x80x9cAutobahnxe2x80x9d, products of Metricom, Inc. of Los Gatos, Calif. Autobahn is a planned, but as yet undisclosed, system that allegedly is going to support 500 Kbps as a raw date rate with a user rate of 128 Kbps at pedestrian mobility. By pedestrian mobility, it is meant at speed equal to or less than 5 kilometers per hour.
Ricochet uses an unlicensed Industrial Scientific Medical (ISM) band at around 900 mega-hertz (MHz) for end-user interface. This wireless network architecture is bandwidth constrained on the order of about 100 Kbps raw data rate for pedestrian is mobility with a user rate of 28.8 Kbps. This system is also transmit-power limited having range below that of a cellular system, resulting in a microcellular architecture with an extensive backhaul network. Moreover, a substantial investment in infrastructure would be needed to match existing cellular capability. Furthermore, such a wireless network architecture has limited in-building penetration.
Because the above-described system architectures have limited data rates, it would be desirable to provide wireless access for untethered users with a higher data rate. Moreover, it would be desirable to provide such wireless access with a longer range and which could be more readily used indoors. Furthermore, it would be desirable to provide such wireless access with seamless roaming from cell to cell.
One aspect of the present invention is a communication system. Such communication system comprises a transceiver operatively coupled to an antenna and a computer system. The antenna may be selected for indoor or outdoor use. The computer system comprises a processor, memory, an input device, an output device and an input/output device. This input/output device is operatively coupled to the transceiver, and may be a radio card. Moreover, the transceiver may be an input/output device of the computer system, and the transceiver and radio card may be combined onto one card or may be separate cards.
Another aspect of the present invention is a wireless area network. Such wireless area network comprises at least one communication system and at least one wireless local area network adapted for broadcast communication with the communication system. The wireless local area network comprises two antennas, a range extender, two converters and a transit conduit for moving data and other information. One converter includes a point-to-point radio having at least a 10 MHz bandwidth, and the other converter includes a point-to-point radio having at least a 10 MHz bandwidth. The wireless local area network may form a cell of a plurality of cells in a wireless metropolitan area network.
Another aspect of the present invention is having a cell configured with at least one antenna, an optional range extender and at least one converter operatively coupled to a flexible backhaul. The flexible backhaul may be operatively coupled to a wide area network.
By functionally coupling the wireless local area network with a wireless metropolitan area network, the invention creates a seamless connection from end to end. Further, the flexible backhaul allows the use of either wired or wireless backhaul in the inventive system, increasing the number of equipment options for the network.
With one or more aspects of the aforementioned, it is anticipated that the broadband user throughput will exceed 1 Mbps, and this data transfer rate can be maintained while moving a communication system equal to or less than 5 kilometers per hour. Furthermore, it is anticipated that broadband user throughput of approximately 1 Mpbs can be maintained while moving a communication system greater than 5 kilometers per hour. Accordingly, this degree of throughput is comparable to wired LAN connectivity, and such connectivity is provided for untethered computing. Moreover, this architecture facilitates seamless roaming from one cell to another cell for portable and mobile computing, and this seamless roaming may be done while maintaining multiple sessions. Moreover, multiple users can access the same cell for shared usage.
These and other features, advantages, objects and embodiments of the present invention will become more apparent from reading the following Detailed Description of the Preferred Embodiments or by practicing the present invention.